This might have been true in the early 00s, but not now: Based on satellite imagery analysis I've seen, large parts of the midwest are doing crop rotation with

This might have been true in the early 00s, but not now: Based on satellite imagery analysis I've seen, large parts of the midwest are doing crop rotation with corn and soybeans in the main season, which more differences in the winder depending on weather. The reason a US farmer chooses what to plant each year is the same as everywhere else: Given the state of their soil, the expected weather in their plots, legislative incentives and some guesses on crop value, they plant whatever they think will keep making the most money. The increase in soybeans as a useful rotation crop come from higher price per bushel vs 2000, and the increase demand making it easier to sell it in their local elevator. The extra $4 a bushel makes it much better than doing all kinds of extra treatments to the soil to keep trying to run more corn. As prices rise and fall, practices change to match. And this is why modifying plants to lower the need of fertilizer can make such a big difference: A crop that before might not have been economical can become more viable. If a farmer has to risk soil health to have a somewhat profitable year, because anything else looks like losing money, they'll take the risk, in the same way that they'll cheap out in their pesticide applications. When the farmers are making good money with safer practices, they'll use them, and they'll keep investing. But for every 2012, when drought raised prices through the roof, and everyone else got their insurance payouts, there's many years where the farmer doesn't cover costs. Always assume that the farmer is doing the best they can to make money, whether they have some organic apple orchard, or they are planting Monsanto soybeans.